A place to discover and learn about laboratory tests performed during pregnancy.

Welcome to The Pregnancy Lab! We created this blog because of our interest in the biochemistry of pregnancy and the different laboratory tests used during pregnancy. It's our hope that this blog will become a resource for anyone interested in gaining a better understanding of laboratory testing during pregnancy.

Monday, February 06, 2017

We have blogged previously about the limitations of urine hCG tests to detect pregnancy in a hospital setting and about the Abbott iSTAT, the first FDA approved device for detection of hCG in whole blood at the point-of-care.

Recently, Nerenz et al evaluated the NOWDiagnostics ADEXUSDx™ hCG test, a qualitative immunoassay device for the detection of hCG in anticoagulant-free whole blood, heparinized whole blood, or heparinized plasma. This device is read visually, like the urine/serum POC devices, but it is FDA approved for the use of whole blood samples.

Overall, the device performed very well for the detection of hCG using capillary fingerstick samples.

The device has several limitations.

The ADEXUSDx product is a qualitative, not quantitative device. This is different than the iSTAT device, that we reported on previously, as the iSTAT is quantitative with a range of 5-2000 IU/L. However, since hCG concentrations in women rise so rapidly in early pregnancy, and with such a narrow dynamic range some would argue that the iSTAT device is almost a qualitative device.

The authors reported that the device recognized 100% of samples at a concentration of 27 IU/L and approximately 50% of samples at a concentration around 10 IU/L. This analytical sensitivity is similar to the POC serum devices currently used in hospitals.

Finally, the ADEXUSDx device showed susceptibility to the high-dose hook effect, as decreasing test line intensity was observed at concentrations ≥600,000 IU/L, but all devices were interpreted as positive. This limitation is similar to that seen with the iSTAT device.

Overall, this is a nice addition to the available POC hCG devices currently on the market. It should be pointed out that the Abbott iSTAT and the NOWDiagnostics ADEXUSDx are the only two devices currently available for the diagnosis of pregnancy using whole blood at the point of care.

Whole blood should not be used on devices that are only FDA approved for urine and/or serum, as we have pointed out in previous publications.

PAMG-1 is present in blood, amniotic fluid (AF), and cervicovaginal fluid of pregnant women. The concentration of PAMG-1 in AF (2,000–25,000 ng/mL) is several thousand times higher than that in cervico-vaginal discharge when the fetal membranes are intact (0.05–0.2 ng/mL). The high concentration of PAMG-1 in AF makes it potentially a good marker to detect the presence of AF in the vaginal canal.

In one of the largest studies, Lee et al examined 184 women with symptoms or signs of PROM. 159 were later confirmed to have PROM. In this population, PAMG-1 demonstrated a sensitivity of 98.7%, specificity of 87.5%, positive predictive value of 98%, and a negative predictive value of 91.3%. In contrast, Nitrazine in the same patients demonstrated a sensitivity of 88.1%, specificity of 87.5%, positive predictive value of 97.9%, and a negative predictive value of 52.5%. This performance is supported by several other studies as well.

Monday, February 15, 2016

Zika virus is a mosquito borne illness that is found in South and Central America. The most common symptoms include fever, rash, joint pain, and conjunctivitis (red eyes). The virus is spread by mosquitos primarily in the Aedes aegypti and Aedes albopictus species which also carry other tropical diseases such as Chikungunya and Dengue. These mosquitos bite humans primarily in the daytime. It is estimated that 80% of people infected with the Zika virus are asymptomatic. In most people with symptoms, the illness is self-limited and resolves in 5-7 days. Disease requiring hospitalization is rare.

Recently, there have been reports in Brazil of an increased rate of microcephaly and other poor pregnancy outcomes in babies from women who were infected with the Zika virus while pregnant. However, further studies are needed to understand the relationship between these outcomes and infection. In the meantime, the Centers for Disease Control and Prevention (CDC) have issued special travel precautions for pregnant women and women trying to get pregnant.

So who should be tested for Zika virus and what testing is available?

Initially, the CDC advised that a pregnant woman should only be tested if she has symptoms of Zika virus within the first week of being in an endemic area. If the mother is positive, then the infant should be tested for congenital infection.

However, very recently, the CDC updated the guidelines to include asymptomatic pregnant women who live in or have traveled to endemic areas. The update recommends that serologic testing be offered to pregnant women can be offered testing within 2-12 weeks after they return from travel. For asymptomatic pregnant women who live in endemic areas, testing is recommended at the initiation of prenatal care with follow-up testing mid-second trimester.

For infants that have microcephaly or intracranial calcifications detected prenatally or at birth with a mother who was potentially infected with Zika virus during pregnancy, the infant should be tested. If infants have positive or inconclusive test findings, the case should be reported to the State or local health department for follow-up. If the infant tests negative, other possible etiologies for the microcephaly should be investigated.

For infants without microcephaly or intracranial calcifications with a mother who was potentially infected with Zika virus during pregnancy, subsequent evaluation depends on the mother's results. If the mother test's negative, no further testing is required. If the mother received positive or intermediate results, then the infant should be tested. If the infant test's negative, then no further testing is required. If the infant test's positive then further clinical evaluation (including comprehensive physical exam, cranial ultrasound and ophthalmologic evaluation) should be performed and the infant should be followed for long term sequelae.

No commercial tests are yet available for Zika virus. Testing is performed at the CDC and some local health departments. The tests currently performed include RT-PCR, ELISA for IgM and a plaque reduction neutralization test (PRNT).

Infants who are being evaluated should have RT-PCR performed on serum (from infant or umbilical cord) within 2 days of birth. CSF if available should also be tested by RT-PCR. ELISA for IgM should be performed on infant serum and CSF.

Mothers being evaluated should have serum tested using ELISA. RT-PCR can be performed during the first week of viral infection. Amniocentesis should be offered to pregnant women who test positive or indeterminate and RT-PCR should be performed on the amniotic fluid.

Note that false positives can occur in the ELISA assay due to cross reactivity with other related flaviviruses such as dengue or yellow fever. PRNT can be used to distinguish false positives from true positive results. If neutralizing antibody titers are ≥ 4-fold greater than dengue virus neutralizing antibody titers, then Zika virus is considered positive. Immunohistochemistry can also be performed on fixed placenta or umbilical cord tissue. If any of any of the tests are positive, the infant is considered congenitally infected.

Currently, there is no anti-viral treatment or vaccination for Zika virus. Treatment is supportive. The best defense against Zika is preventing maternal infection by avoiding mosquito bites. It is important to note that, when used as instructed, insect repellants containing DEET, picardin, and IR3535 are safe for pregnant women.

Tuesday, January 19, 2016

We have blogged previously (here and here) about false negative results in qualitative point-of-care (POC) hCG devices due to high concentrations of hCGβcf in urine. We have shown that the majority of qualitative POC hCG devices are actually susceptible to false negative results due to saturation of capture antibodies by high concentrations of hCGβcf. These findings have led to an increased interest in urine hCGβcf measurements.

However, only a few research laboratories quantify hCGβcf, so it is difficult for most clinical laboratories to determine which urine samples have high concentrations of this hCG variant.

Previously, we demonstrated that the Roche Cobas hCG+β assay detects hCGβcf but the Abbott Architect Total β-hCG assay does not. Using that information, in a recent study, we examined the correlation between hCGbcf concentrations as measured by LC-MS/MS and the absolute difference between urine hCG measurement using the Roche Cobas and Abbott Architect assays in fourteen urine samples. The correlation between hCGβcf concentration measured by LC-MS/MS and the Roche-Abbott difference was excellent (r=0.97).

This study indicates that the difference in urine hCG concentration when measured by two automated immunoassays (one that recognizes hCGβcf and one that does not) provides a robust estimate of the urine hCGβcf concentration. Using the linear regression equation (Roche-Abbott difference (in IU/L) = (hCGβcf (pmol/L)*0.131+656)), a urine hCGβcf of 280,000 pmol/L translates into an approximate Roche-Abbott difference of 37,336 IU/L.

There are many unanswered questions about hCGβcf, including: How high do hCGβcf concentrations get during pregnancy? Are some women prone to higher hCGβcf concentrations? Are high hCGβcf concentrations associated with certain clinical symptoms or pathological conditions? The ability to estimate the amount of hCGβcf in urine will allow many more laboratories to study the concentrations of this interesting hCG variant.

Monday, October 26, 2015

“How early can pregnancy be detected?” is a question we are asked all the time. The short answer is, “It depends.” Let’s answer this question one step at a time.

First, the most common way to detect early pregnancy is by measuring the hormone human chorionic gonadotropin (hCG). If an egg is fertilized, the developing embryo will attach to the lining of the uterus around 6-12 days after ovulation. This is called implantation. The hormone hCG is produced by trophoblastic cells (the outer layer of the embryo) after implantation. It takes several days for hCG to be detectable in blood or urine. hCG production increases very rapidly with serum concentrations doubling every 1-1.5 days in the first 8-10 weeks of pregnancy. So, detecting pregnancy first depends on how quickly implantation occurs.

Second, it depends on the sample in which hCG is measured; blood or urine. Urine concentrations of hCG are almost always lower than serum concentrations. In addition, urine concentrations of hCG can be affected by fluid intake. If large amounts of fluids are ingested (think Big Gulp) then urine concentrations will be more dilute. This is why first morning urine samples are often recommended because this urine is usually the most concentrated of the day since people don’t tend to drink anything during the sleeping hours. The amount of water in blood is more regulated that that of urine and generally does not change, even after ingesting large amounts of liquid. Therefore, use of a blood sample will generally detect pregnancy earlier than use of urine.

Third, it depends on the method used to detect hCG; qualitative or quantitative. Qualitative devices are those that can be purchased over-the-counter to detect hCG in urine. They are also used in hospitals and doctor offices. These devices generally have cutoffs for positivity that vary from about 20-50 IU/L. The cutoff varies widely by brand. Interestingly, we have shown that the devices used at home are often more sensitive than the devices used in the hospital!! We have previously blogged about this topic. Quantitative hCG assays are performed using blood samples in laboratories and are much more analytically sensitive than qualitative assays. Most quantitative hCG assays can detect hCG at concentrations of 2 IU/L and some can go as low as 0.1 IU/L. Therefore, quantitative assays will be able to detect pregnancy earlier than qualitative assays.

Fourth, when the clinical sensitivity of an hCG test for diagnosing pregnancy is determined, it is usually determined as a function of the number of days relative to the expected day of the menstrual period (EMP). How early an hCG test can detect pregnancy depends on how the EMP is estimated. Most women estimate EMP by counting 28 days from the first day of the last menstrual period (LMP). This 28-day cycle includes the approximate 14 days between first day of menses and ovulation (called the follicular phase) and the approximate 14 days between ovulation and the day before the next menstrual period (called the luteal phase). However, the length of menstrual periods varies between women. Studies have shown that most of the variation occurs in the follicular phase.Therefore, the most accurate way to estimate the EMP is by measuring 14 days from ovulation as estimated by detecting a dramatic rise in the concentration of luteinizing hormone (LH), commonly referred to as the LH surge. Using 14 days from the LH surge can detect 100% of pregnancies by the EMP, as opposed to using 28 days from LMP which did not detect 100% of pregnancies until 7 days after EMP. By measuring serum hCG, 100% of pregnancies can be detected by EMP and nearly all pregnancies can be detected by 3 days before EMP.

In summary, how early pregnancy can be detected depends on many factors. In some cases pregnancy can be detected more than 3 days before EMP. Virtually all pregnancies should be detected by one week after EMP.

Monday, October 05, 2015

"A question some women face: when to freeze their eggs." This was the start of a news piece I heard on NPR as I drove to work this morning. It caught my attention and I realized we haven't spent much time on this blog exploring the tests used to help achieve pregnancy.

The premise of "ovarian reserve" testing is rather straightforward: they are supposed to help a woman concerned about fertility decide whether she should freeze her eggs for future use or if she can wait to conceive because time is still on her side.

Unlike sperm, which are produced continually over a man's reproductive lifetime, the number of eggs in the female ovaries peaks during fetal development, declines over time, and do not regenerate. Thus, female fertility declines with each year of life. Tests of ovarian reserve are supposed to reflect the number and quality of remaining eggs, a key element in reproductive potential. Ovarian reserve tests include both blood tests and ultrasound tests. This post will focus on the blood tests.

FSH

With normal ovarian function, the developing eggs in the ovary secrete hormones which keep the concentration of follicle-stimulating hormone (FSH) in its normal range during the first few days of the menstrual cycle. When the number of developing eggs is decreased, the concentration of FSH is increased. Thus, measuring FSH on day 3 of the menstrual cycle is a test of ovarian reserve and higher values are associated with lower fertility.

Estradiol

Estradiol is released from developing eggs during the first few days of the menstrual cycle. Estradiol concentrations are usually low during days 2-4 but increase thereafter. A high value at this time suggests poor ovarian reserve.

AMH

Anti-Müllerian hormone (AMH) is produced by the granulosa cells of eggs and so its concentration reflects the size of the ovarian pool of eggs. As the number of eggs declines, so too does AMH. But while the concentration of AMH predicts the quantity of eggs, it does not predict their quality.

Inhibin B

Inhibin B is another hormone released by eggs and so it is similar to AMH in evaluating the number of eggs in the ovary. Because inhibin B helps to regulate FSH concentrations, a low inhibin B is associated with a high FSH. Unlike AMH, inhibin B shows a lot of variation across menstrual cycles so it's not a recommended test of ovarian reserve.

Clomiphene Citrate Challenge Test

Clomiphene is a selective estrogen receptor modulator that causes the pituitary gland to release the hormones needed to stimulate ovulation. This test is performed by measuring FSH on cycle day 3 (before giving Clomiphene) and again on day 10 (after giving Clomiphene, daily, on days 5-9). In women with normal ovarian reserve, the rising inhibin B and estradiol concentrations produced from the developing eggs would suppress FSH. However, in women with decreased ovarian reserve, FSH is elevated on day 10 due to the lower concentrations of inhibin B and estradiol.

Not surprisingly, no single test is adequate to evaluate a woman's ovarian reserve. To address that, it is not unusual for doctors to perform several of these tests in an effort to provide a more definitive answer. Unfortunately, there is still no universally agreed upon definition of "decreased ovarian reserve" and evidence of decreased reserve (biochemical or otherwise) does not correlate very well with the inability to conceive.

So while there is a very strong desire to have definitive tests to predict a woman's fertility potential in an effort to help her decide if she can wait to conceive or take action such as harvesting and freezing eggs for future use, such answers are not yet available from lab tests alone.

Tuesday, July 28, 2015

Personalized medicine can be defined as customized disease prevention therapies and drug treatment protocols based on knowledge of an individual’s unique genetic makeup, metabolic profile and clinical presentation. So far, personalized medicine has focused on the prevention and treatment of conditions affecting adults such as cancer and cardiovascular disease. However pregnancy is a unique situation where the unique characteristics of two individuals are being assessed: mother and infant. Remarkably few studies have addressed the therapeutic implications of recent advances in genetic technologies for the fetus. Focus has been more on prenatal diagnosis than on fetal treatment. As molecular technologies advance and costs decrease, targeted genetic testing and even whole genome sequencing of the fetus are likely to become more available. This brings with it a number of ethical issues especially as it relates to testing of the infant. For instance, there are questions of informed consent, confidentiality of results, the clinical significance of genetic polymorphisms and decisions to terminate pregnancy on the basis of these test results.

Nonetheless, there have been some interesting advances in personalized medicine, for both mother and fetus, during pregnancy. This is the focus of an upcoming symposium at the AACC meeting to be held tomorrow, July 29th, at 10:30 am in Atlanta, Georgia.

Predicting Response to Drugs: Sixty-four percent of women in the US are prescribed more than one drug during pregnancy (excluding vitamins). A better understanding of how drugs are metabolized during pregnancy and how they affect the fetus is clearly needed. Cytochrome P450 is the predominant class of oxidative enzymes that catalyze many types of drugs. Interestingly, the expression of a number of P450 genes is altered during pregnancy. Most notably, CYP1A2 has been shown to be decreased by 65% by the 3rd trimester. In the past several years, several studies have examined the ability to predict a woman’s response to drugs used during pregnancy, like tocolytics and anti-emetics, based on their genotype. A study by Haas, et. al. demonstrated that CYP3A5 high-expressing women had lower circulating concentrations of Nifedipine, a common tocolytic. A study by Lehmann, et. al. demonstrated that a genotype for serotonin receptor subunits 5-HT3A and 5-HT3B may play a role in hyperemesis severity and response to anti-emetics. This type of genotyping is not yet ready for prime time, but it holds promise for better utilization of medications during pregnancy.

Assessing the Fetus: We have blogged previously about cell free fetal DNA (cffDNA) in maternal blood and its utility in predicting fetal trisomy. cffDNA can also be used to assess fetal Rhesus D (RhD) status. This method can be used to determine the fetal RhD genotype when the mother has clinically significant alloantibody to the D antigen AND the father is heterozygous for RhD or is not available for testing. Testing such as this is useful because instead of treating all RhD-negative women with RhD immunoglobulin, treatment can be targeted to mothers that carry RhD-positive fetuses. This type of approach can conserve supplies of therapeutic anti-D, prevent unnecessary administration of a human-derived blood product to a vulnerable patient group, and avoid subjecting RhD-positive infants to intensive antenatal monitoring to predict and treat fetal anemia. Interestingly, despite the fact that the American College of Obstetricians and Gynecologists support the use of cffDNA for RhD assessment, it is not a widely used clinical tool in the United States.

Predicting Viability: Not all personalized medicine is genetic. Personalized medicine can also be used to guide treatments. With this in mind, there are several publications that suggest novel uses for hCG testing. The first takes advantage of “semi-quantitative” urine hCG devices. These devices are similar to home pregnancy devices, but they essentially contain multiple detection strips with different cutoffs that can give the reader a rough estimate of the urine hCG concentration (>25, >100, >500, >2000 or >10,000). Several studies have examined the use of these devices in a home setting following medical abortion as a replacement for clinic follow-up. If the woman is able to demonstrate decreasing hCG concentrations at home, she can avoid a return visit to the clinic. This can reduce the burden on the healthcare setting, but it could also help women for whom getting to a clinic is difficult because of work or family commitments or who live in a remote geography. Both studies demonstrate that use of semi-quantitative hCG devices in this setting had 100% sensitivity to detect unsuccessful abortions. The second interesting use for hCG measurement is in the prediction of fetal viability. Several studies have suggested that urine and serum concentrations of hyperglycosylated hCG (hCG-H) are low in women with pregnancy failure. These studies suggest that measurements of serum or urine hCG-H to detect failed pregnancy is 60-70% sensitive and 97-100% specific (links here and here). These studies are small and there is not currently a readily accessible assay for hCG-H, but it is intriguing to think about the possibility of a test that could distinguish viable from non-viable pregnancies especially in an emergency setting when physicians are making treatment decisions and have to take into account potential risks to the fetus.

Tuesday, July 21, 2015

This post was written by Robert D. Nerenz, PhD, an assistant professor of pathology and laboratory medicine at the University of Kentucky, in Lexington.

In the United States, an estimated one in seven couples experience infertility and for many of these couples, in vitro fertilization (IVF) represents their best chance of achieving pregnancy. However, IVF cycles constitute a significant expense (approximately $12,500 per cycle), disrupt patients’ daily lives and only result in a healthy, live birth 30% of the time! Furthermore, the majority of IVF cycles performed in the United States involve the transfer of multiple embryos. This is of particular concern because multiple embryo transfer carries a finite risk of a multiple gestation pregnancy. Bringing multiple infants to term is associated with an increased risk of poor fetal and maternal outcomes including decreased birth weight, increased rate of fetal death, preeclampsia, gestational diabetes and preterm labor. Clearly, there is a significant need to improve IVF success rates while also minimizing the likelihood of multiple gestation pregnancies.

One strategy that may accomplish both of these goals is to perform “single embryo transfer” by implanting one embryo that has a high likelihood of producing pregnancy and, ultimately, a live birth. This is the focus of an upcoming symposium at the AACC meeting to be held July 29th at 10:30 am in Atlanta, Georgia. Fertility clinics around the world currently attempt to do this by observing embryos under a microscope and choosing the best embryo on the basis of its physical appearance. Unfortunately, this approach does not provide any information about the embryo’s genetic status. This is an important limitation because aneuploidy (the gain or loss of a chromosome) is the most common cause of pregnancy loss. It is also estimated to occur in ≥10% of clinical pregnancies and becomes more frequent with increasing maternal age.

The ability to transfer only euploid embryos represents the most promising application of novel technologies to IVF but ongoing research is focused on other ways to improve the IVF success rate. Many different groups are analyzing the culture medium that embryos are grown in prior to implantation. It is hoped that this will provide information about the embryos’ metabolic health and might help identify which embryos are most likely to result in pregnancy and live birth. Other groups are evaluating endometrial gene expression profiles to assess endometrial receptivity and ultimately determine the best time to perform embryo transfer. While both of these approaches have technical limitations and are not quite ready for primetime, they have the potential to greatly improve our current standard of care and may be ready for clinical use in the near future.

Monday, July 06, 2015

The American Congress of Obstetricians and Gynecologists (ACOG) have updated their guidance on cell-free DNA (cfDNA) screening tests for fetal aneuploidy. In it, they state that any patient (i.e. women at high-risk OR low-risk for having an affected pregnancy) may choose cfDNA testing but they caution that conventional screening tests are more appropriate. This document replaces an earlier opinion, published in 2012, which clearly stated that cfDNA screening tests should not be offered to the general obstetrical population because they are considered to be at low-risk.

So ACOG went from recommending that cfDNA testing not be performed on low-risk women to say that they may choose cfDNA testing. Why the subtle change? Well, as ACOG correctly notes, the landscape of cfDNA is changing rapidly. New studies are published frequently and those that have examined the performance of cfDNA tests in low-risk women have reported that the test performs just as well in them as it does in high-risk women.

However, they make an important point about a metric that doesn't get the attention it deserves. The positive predictive value (PPV). See here for background. Because the prevalence of fetal aneuploidy in low-risk women is lower than it is in high-risk women, a "positive" or "abnormal" test result in low-risk women is more likely to be a false-positive result. For example, a positive result in a 25-year-old woman gives a 33% chance that the fetus is affected but that chance increases to 87% in a high-risk woman.

The report also calls out the "no result" problem. cfDNA tests fail to produce a result in 1-8% of samples tested, usually due to a low amount of fetal DNA in the blood sample. It's becoming clear that women with samples that fail to produce a result are at increased risk of having an affected fetus. According to ACOG, these women she be offered diagnostic testing such as fetal karyotyping using amniotic fluid obtained by amniocentesis.

Other notable points contained within the updated guidance include:

Caution about not routinely performing microdeletion screening (offered by some labs) because it has not been fully validated in clinical studies.

Clearly indicating that a negative or normal result does not rule out the possibility of an affected fetus.

Providing genetic counseling to patients about test limitations and that decisions such as pregnancy termination should not be based on these screening tests.

A reminder that cfDNA tests do not screen for neural tube or ventral wall defects

This certainly won't be the final say that ACOG has on cfDNA aneuploidy screening tests. Indeed, they state that "It will be critical to remain abreast of this rapidly changing technology to provide patients with the most effective, accurate, and cost-conscious methods for aneuploidy screening."

Monday, May 18, 2015

Testing urine samples for the presence or absence of hCG is commonly performed in hospitals and clinics for the rapid assessment of a woman's pregnancy status. This topic has been discussed several times in this blog (see here and here).

Because of these limitations, in particular the risk of false negative results, I've often said that urine hCG testing is inappropriate in healthcare delivery settings. Blood tests for hCG are much more reliable but they take longer to produce results because of the time required for sample transport and processing by a centralized laboratory.

We evaluated the test using whole blood and plasma (the sample types that were cleared for use) as well as serum. Overall, the test works quite well in all sample types and is suitable for use in healthcare settings. It provides the reliability of laboratory blood-based hCG testing but with the convenience of point-of-care testing.

There are two important limitations to note:

The analytical measuring range of the i-STAT hCG test is limited to 5-2,000 IU/L. While this is similar to the measuring ranges of many laboratory hCG tests, the instruments used in labs can automatically dilute and re-test samples that have a high hCG concentration, something that the i-STAT is unable to do. When tested with the i-STAT, a sample with an hCG concentration greater than 2,000 IU/L will be reported as such. While this type of result indicates that hCG is present in the blood, not having an absolute concentration will be insufficiently informative in some clinical situations.

The test is susceptible to the high-dose hook effect at an hCG concentration somewhere between 400,000 and 600,000 IU/L. This means that when a sample with an extremely high hCG concentration is tested, the result can be falsely decreased. However, even though the result is falsely decreased, it is still very likely to be interpreted as "positive" and the risk of a false-negative result is extremely remote.

This type of test is long overdue in the US. The use of urine hCG testing to determine a woman's pregnancy status is fraught with difficulties and is known to cause harm to patients. Despite their problems, urine hCG testing won't be going away any time soon but the availability of a test that performs hCG blood tests close to the patient is a step in the right direction.